326 



COMMON WEEDS 



plant is spread by means of its rootstock and by small 

 seeds, which ripen into a berry above water. 



The White Water-lily (Nymphcea alba L.) is also 

 found in slow-moving streams and in ponds of clear 

 water. The leaves have very long stalks and floating 

 leaf-blades, which are circular, with cordate base. It is 

 propagated by its strong fleshy rootstock, and by the 

 seeds which are produced in a capsule ripening under 

 water. 



HALORAGE^: 



Mare's Tail (Hippuris vulgaris L.) is a common 



aquatic perennial at the 

 edges of ponds and slow- 

 moving streams. It has a 

 stout creeping rootstock, and 

 erect round stems about 

 to J of an inch in dia- 

 meter (Fig. 92). The leaves 

 are very narrow/ about an 

 inch long, and arranged in 

 whorls six to twelve to- 

 gether at each of the many 

 joints. 



The flowers are green, 

 very small, with no petals, 

 and only one stamen. 



Water Starwort (Calli- 

 triche vema L.) is a very 

 variable species, abundantly 



i>. 92. J-,en : vvaieroiarwomoa^z- . / 



triche verna L.), x |. Right: distributed 111 the Water of 



Mare's Tail (Hippuris vulgarisL.), nnnr i B rUtrhpc onH clnw 



x i, with fruit enlarged. ponds, QltCneS, and SlOW 



streams throughout the 



country, and often found growing on mud by the side 

 of ponds. Watercress growers frequently complain of 



FIG. 92. Left : Water Starwort 



